Fatty acid salts of polyhydroxy amines



Patented June 24,1941.

UNITED STATES PATENT OFFICE ra'rrr horn SALTS or POLYHYDROXY amass 1Byron M. Vanderbilt, Terre Haute, lnd., assignor to Purdue ResearchFoundation, La Fayette.' hit, a corporation of Indiana No Drawing.Application August is, 1937,

Serial No, 158,954

6 Claims. '(cl. 260-404) My invention relates to salts of animohydroxycompounds useful as emulsifying agents, and the I like. a Moreparticularly, it relates to higher fatty acid salts of theaminopolyhydroxy compounds useful as emulsifying agents.

these materialsyhowever, are such as to limit their general use.

I have now discovered that higher fatty acid salts ofthe-polyhydroxyamines areparticularly The term emulsion covers a widevariety of products of varying characters which consist essentially ofparticles or droplets of a liquid suspended'in another liquid. Familiarexamples of emulsions ar homogeneous mixtures of oil or Such mixturesare ordinarily suspended in the water this type of emulsion is known asthe oil-in-water (O/W) type. If the oil is the continuous phase of theemulsion and water droplets are suspended therein, the emul sion is thewater-in-oil (W/O) type. The formertype may be readily diluted withwater and the latter only with oil.

Emulsions often possess unusual and desirable properties per se. In manyinstances, however, they are employed as a means of obtaining suitabledilutions of various materials which may not be satisfactorily used inconcentrated form.

Emulsifying agents are used commercially for the production of emulsionssuitable for many pur-.

poses including. insecticides, disinfectants, or-

chard sprays, polishes, lotions, creams, inks, etc.

The selection of an emulsifying agent for a particular purpose'isdeterminedby such factors as stability of the. material, its tendency toaffect unfavorably any of the-constituents of the dispersion, andtheamounts required to give a dispersion of the desired character. Itshould have the property of keeping the emulsified materials in adispersed condition for the desired period of time. Examples ofemulsifying agents previously suggested for various purposes includesuch materials as sulfonated oils, sulfonated high molecular weightalcohols, triethanolamine salts of fattyacids, certain gums andproteins, polyhydric alcohols which have 'been incompletely esterifiedwith high molecular weight may acids, metallic soaps, etc. .Theproperties of most of those produced by oil and water with the aid ofsome emulsifying agent. If the oil droplets are suited for use asemulsifying agents. The polyhydroxyamines which react with the fattyacids have the following general formula:

to form the emulsifying agents of my invention wherein X representshydrogen, an alkyl or a methylol group; Y represents hydrogen or analkyl group; and Z represents a hydrogen or, in,

case X is a hydrogen, Z may also represent an alkyl group.

These aminohydroxy compounds may be still further. defined as thoseaminohydroxy compounds obtainable by the catalytic reduction of thecorresponding nitrohydroxy compounds which can be prepared by the actionof aliphatic aldehydes on primary aliphatic nitroparaflins. Thepreparation of these compounds are described fully in U. S. Ser. No.151,155 filed by B. M. Vanderbilt on June 30, 1937, and U. S.

Serial No. 151,841 filed by Kenneth Johnsonon July 3, 1937. Specificexamples of aminohydroxy compounds included by this formula are 2amino-2methylol-'1,3-propanediol, 2-amino-l,3- propanediol,2-amino-2-methyl-1,3-propanediol, and2-amino-2-isopropyl-1,3-propanediol.

These new emulsifying agents and emulsions containing them may beprepared in a variety of ways. If, for example, it is desired to use thesalts of the-various hydroxyam'ines directly, they may be prepared byadding the amino compound to an equivalent amount of a higher fatty acidat room or elevated temperatures and in the presence or absence of anauxiliary solvent such as ethyl ether.v The salts thus prepared may beadded directly to a mixture of oil and water with vigorous agitation.emulsions utilizing the salt of the aminohydroxy compound are preparedin one of the following ways: First, the amino compound and fatty acidare dissolved in a part of the oil and then the water and the rest ofthe oil are added alternately with good agitation. Second, a water, sovthe amino compound and fatty acid in all of the oil is prepared whichemulsifles spontaneously when added to water. Fourth, the emulsificationPreferably, however,

is brought about instantly by stirring together two solutions, one ofwater and the amino compound, and the other of the oil and fatty acid.

The concentration of emulsifying agent to be used will vary widelydepending upon the emulsifying agent employed, the emulsion to beprepared, the desired characteristics of the resulting emulsion, etc. Ihave found that fairly stable emulsions of naphtha and 90% water may beprepared by using as little as 175% of a salt of an aminohydroxycompound such as 2- amino-2-methylol-1,3-propanediol oleate or 2-amino-2-methyl-1,3-propanediol oleate, although for most purposes Iprefer to use approximately 3.0% of the salt. Suitable concentrations ofemulsifying agents for various emulsions may then diluted with 200 cc.of water, agitated vigorously for 3 minutes and allowed to stand atreadily be determined by simple experimentawhile those containing fewercarbon atoms such as 2-amino-2-methyl-1,3-propanediol form theoil-in-water type emulsions. It will be readily recognized from thegeneral structural formula given in the above that there are a lar enumber of aminohydroxy compounds that may be employed as higher fattyacid salts according to the teaching of my invention. The choice ofcompound will depend to some extent upon the .type of emulsion to beprepared and the materials to be emulsified. Those higher aminohydroxycompounds which are insoluble in water, or nearly so, will, in general,not be so satisfactory as the lower ones of greatersolubility. Thesolubility of these compounds will depend upon the molecular weight, thenumber of hydroxyl groups present and the presence or absence ofbranched chains in the molecule.

In general, stoichiometric quantities of the room temperature.

The oleate of 2-amino-2-methyl-L3-propanediol gave a good O/W typeemulsion'when used as indicated above which became slightly curdy in 3days. If a 5% excess oleic acid was used when preparing the emulsion,two layers formed at once, and if 5% excess of the base was used, the'O/W emulsion was stable for six days. When the stear'ate was used,layer separation occurred in a few hours. Similarly, the oleateof2-amino-2-methylol-1,3-propanediol gave a good O/W type emulsion stableafter six days, and the oleate of 2-amino-2-isopropyl--1,3-propanediolgave a very stable. emulsion of the W/O type.

It is to be understood that any of the higher fatty acids or mixturesthereof may be used for preparing the emulsifying agents of myinvention.. For example, any of the fatty acids or mixtures thereofobtained .by. the saponiflcation vegetable or mineral .waxes, fats,oils, greases,

etc. The aqueous emulsions of these various oily materials are referredto in the appended claims aminohydroxy compound and fatty acid are-.used

to give the emulsifying agents of my invention in order to impartdesirable properties to the emulsions produced but an excess of eithermaterial may be used without departing from the scope of my invention.In fact, a slight excess of one or the other constituent in certaincases gives more stable emulsions than when equivalent quantities ofbase and acid are used. Thus, in general, it may be stated that anexcess of higher fatty acid used in the emulsifying agent will tend toincrease the stability of a water-inoil emulsion, and, conversely, anexcess of aminohydroxy compound will tend to lend more stability to anoil-in-water emulsion.

The following example will illustrate the method of producing my newemulsifying agents and their use in emulsions, but it is to beunderstood that the invention is not to be limited thereby: To 0.02 moleof the amino compound dissolved in 31 cc. of water there was added to0.02 mole of oleic acid dissolved in 38 cc. of petroleum naphtha boilingat 160-175" C. The mixture was as oil-water emulsions, irrespective ofwhether they are oil-in-water emulsions or water-in-oil emulsions.

What I claim is:

1. A higher fatty acid salt of an aminohydroxy compound of the followinggeneral structural formula:

H x H r 1 wherein X represents a member of the class consisting ofhydrogen, methylol and alkyl groups,

Y and Z represent members of the class consisting of hydrogen and alkylgroups, and wherein at least one of the constituents, X and Z,represents hydrogen.

2. A higher fatty acid salt of 2-amino-2- 6. The stearic acid salt of'2-amino-2-methyl- 1,3-propanediol.

' BYRON M. VANDERBILT.

